Multi compartment collapsible tank

ABSTRACT

A collapsible tank comprises a flexible unitary container having an inner surface and an outer surface and a flexible partial container having an inner surface and an outer surface. The inner surface of the unitary container defines a first compartment for storing a first fluid. The partial container is mounted to the unitary container to divide the unitary container into a first portion and a second portion and to form a second compartment between the inner surface of the partial container and the outer surface of the second portion of the unitary container to store a second fluid. The second portion of the unitary container is flexible and movable relative to the first portion of the unitary container and the partial container to reciprocally change the relative volumes of the first and the second compartments.

FIELD OF THE INVENTION

The invention relates to a collapsible tank for storing fluid. In one aspect, the invention relates to a collapsible multi-compartment tank for storing diverse fluids. In another aspect, the invention relates to a collapsible tank having expandable and collapsible compartments for storing different or the same fluids.

DESCRIPTION OF THE RELATED ART

When fuel-powered machinery and equipment operate in remote locations or locations that are distant from a fuel source, supplying fuel to the machinery and equipment can be problematical. Either the machinery and equipment must be transported to the source of fuel, or the fuel has to be delivered to the remote location. In the latter case, fuel can be stored at the remote location in a collapsible tank that can be easily compacted and stowed for transportation to another location, if desired.

A similar problem arises with respect to the supply of water and other fluids in remote locations. As with fuel, the water can be stored in a collapsible tank, but the tanks for fuel, water, and other fluids are typically single purpose tanks because the material used in the tank construction must be compatible with the specific fluid stored therein. The base material for these tanks is commonly made from a woven nylon that is coated with a flexible thermoplastic polymer to render the material impermeable to the specific fluid. For example, the tank comprises a woven nylon material coated with a polyether polymer when the tanks are to be used to store water and with a polyester polymer when the tanks are used for fuel storage. As a result, a tank inventory must include multiple types of tanks corresponding to the different fluids compatible with each tank.

SUMMARY OF THE INVENTION

According to the invention, a collapsible multi-compartment tank comprises a unitary container formed of a first contiguous wall having an inner surface and an outer surface, the inner surface of the first contiguous wall defining a first compartment for storing a first fluid and a flexible partial container formed of a second contiguous wall having an inner surface, an outer surface and an open end. The open end of the second contiguous wall is mounted to the first contiguous wall to divide the first contiguous wall into a first portion and a second portion and to form a second compartment between the inner surface of the second contiguous wall and the outer surface of the second portion of the first contiguous wall for storing a second fluid.

The relative sizes of the first contiguous wall and second contiguous wall can vary over a wide range depending on the intended uses of the tank. In an illustrative embodiment of the invention, the second contiguous wall is about half of the size of the first contiguous wall and the first and the second compartments have comparable maximum capacities.

The second portion of the first contiguous wall is flexible and is movable relative to the first portion of the first contiguous wall and relative to the second contiguous wall to change the relative potential volumes of the first and the second compartments. Thus, an increase in the maximum volume of one of the first and the second compartments corresponds to a decrease in the maximum volume of the other of the first and the second compartments. In a preferred illustrative embodiment of the invention, the maximum volumetric increase and decrease of the first and the second compartments are of substantially equal magnitude.

Typically, a fill/discharge assembly, a vent, and a drain are mounted to each of the first contiguous wall and the second contiguous wall for filling and dispensing the liquid in each of the compartments.

The first contiguous wall preferably comprises a fluid barrier to prevent fluid in one of the compartments from leaching into another compartment. In one illustrative embodiment, the fluid barrier comprises an inner surface fluid barrier on the inner and outer surfaces of the first contiguous wall. In one illustrative embodiment, the inner surface fluid barrier and the outer surface fluid barrier comprise a polymer coating. In another illustrative embodiment, one of the inner surface fluid barrier and the outer surface fluid barrier comprises a polyester coating and the other of the inner surface fluid barrier and the outer surface fluid barrier comprises a polyether coating. Further, the second contiguous wall comprises an inner surface fluid barrier on the inner surface thereof. Preferably, the inner surface fluid barrier of the second contiguous wall comprises the same material as the outer surface fluid barrier of the first contiguous wall. In one embodiment, the inner surface fluid barrier of the second contiguous wall and the outer surface fluid barrier of the first contiguous wall comprises one of a polyester and a polyether coating.

The first and second contiguous walls are joined together in a secure joint, preferably with a lap joint at a junction between the first contiguous wall and the second contiguous wall. In one illustrative embodiment, the lap joint is thermowelded.

The two or more compartments that are formed by the tank according to the invention can be filled with a wide variety of fluids. Typically, the compartments may be filled different fluids, conceivable remarkably different fluids such as aqueous fluids, such as water, and organic fluids, such as fuel oil. The coatings on the inside surfaces of the compartments will be selected to provide a barrier to the fluids for which the tanks are adapted.

Further according to the invention, a collapsible tank comprises a flexible container having an interior surface that defines a maximum volumetric capacity and a flexible partition secured at its edges at the interior surface of the container to divide the interior of the tank into a first compartment with a first volume for storing a first fluid and a second compartment with a second volume for storing a second fluid. The partition is of a size and pliability that it is movable within the container to reciprocally change the first and second volumes within the tank.

In a preferred embodiment of the invention, the partition is sized so that first and second compartments each have a maximum capacity comparable to the maximum volumetric capacity of the container.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a collapsible tank according to the invention.

FIG. 2 is a schematic top view of the container of FIG. 1.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1 showing a first compartment filled to its maximum capacity.

FIG. 4 is a sectional view similar to FIG. 3 with a second compartment filled to its maximum capacity.

FIG. 5 is a sectional view similar to FIG. 3 with each of the first and the second compartments partially filled.

FIG. 6 is an enlarged view of the region labeled VI in FIG. 3.

FIG. 7 is an enlarged view of the region labeled VII in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the figures and particularly to FIGS. 1-5, a multi-compartment collapsible tank 10 according to the invention can be used to store a single fluid, such as fuel or water, or two dissimilar fluids, such as water and fuel. The tank 10 comprises a unitary container 12 having an inner surface 14 and an outer surface 16 and defining a first compartment 18 with a corresponding first volume. The container 12 is formed from one or more pliable fabric panels that are thermowelded at the seams thereof to form a water tight compartment 18. The tank 10 further comprises a partial container 22 formed from flexible panels that are thermowelded together at their seams to form inner and outer surfaces 24, 26 and an open end. The open end of the partial container 22 is attached to the unitary container 12 at a central region of the container 12 through a continuous lap seam 50 to thereby form a second compartment 28 with a second volume with the outside surface 16 of that section of the unitary container 12 within the lap seam 50. The wall of the partial container 22 is about half the size of the wall of the unitary container 12. That part of the wall of the container 12 that forms the second compartment 28 with partial container 22 is designated portion 12B whereas the other part of the wall of container 12 is designated portion 12A.

The unitary container 12 and the partial container 22 are made of a flexible material so that they can collapse onto themselves to form a compact configuration. For example, the unitary container 12 and the partial container 22 can be formed of woven nylon panels coated with a fluid barrier, such as a polymer, to render the nylon impervious to a first fluid stored in the first compartment 18 and to a second fluid stored in the second compartment 28. The particular type of fluid barrier is selected based upon the types of fluids stored in the first and the second compartments 18, 28. For example, when the first fluid is water, the inner surface 14 of the unitary container 12 is preferably coated with a polyether polymer, and when the second fluid is fuel, the outer surface 16 of the unitary container 12 and the inner surface 24 of the partial container 22 are coated with a polyester polymer. When either of the compartments 18, 28 are filled with a food-grade substance, the corresponding surfaces of the unitary container 12 and the partial container 22 are preferably coated to comply with requirements set by the United States Food and Drug Administration (FDA). The fluid barrier prevents leakage of the first and the second fluids from the tank 10 and also prevents cross contamination between the first and the second fluids.

Referring particularly to FIGS. 3-5, the second portion 12B essentially functions as a flexible partition between the first portion 12A of the unitary container 12 and the partial container 22. In other words, the second portion 12B can be viewed as a flexible partition within a collapsible tank formed by the first portion 12A of the unitary container 12 and the partial container 22. When the tank if filled to capacity, the volumes of the first and second compartments 18, 28 are reciprocal and vary depending on the position of the second portion 12B relative to the first portion 12A and to the partial container 22. Because the partial container 22 and the second portion 12B are of substantially equal size, the maximum volume of the first and the second compartments 18, 28 is equal, as shown in FIGS. 3 and 5. The maximum volume of the first compartment 18 is achieved when the first compartment 18 is filled and the second compartment is empty so that the second portion 12B of the container 12 abuts or nearly abuts the inner surface 24 of the unitary container 22, as viewed in FIG. 3, and this condition corresponds to a minimum volume of the second compartment 28. Likewise, the maximum volume of the second compartment 18 is achieved when the second compartment 28 is filled and the first compartment 18 is empty so that the second portion 12B of the unitary container 12 abuts or nearly abuts the inner surface 14 of the first portion 12A, as viewed in FIG. 4, and this condition corresponds to a minimum volume of the first compartment 18. As the second portion 12B of the container 12 moves between these two extreme positions, as shown in FIG. 5, an increase in the volume of one of the first and the second compartments 18, 28 corresponds to a decreased of the same magnitude in the maximum volume of the other of the first and the second compartments 18, 28. The maximum volumes of the first and the second compartments 18, 28 are reciprocal or compensatory such that the sum of the maximum volume of the first and the second compartments 18, 28 is substantially equal to the maximum volume of one of the individual compartments 18, 28.

As shown in FIGS. 1-5, the tank 10 further comprises a pair of fill/discharge assemblies 30, 32, a pair of vents 34, 36, and a pair of drains 38, 40, wherein one member of each pair corresponds to one of the first and the second compartments 18, 28. In particular, the fill/discharge assembly 30, the vent 34, and the drain 38 are attached to the first portion 12A of the unitary container 12 and correspond to the first compartment 18. Similarly, the fill/discharge assembly 32, the vent 36, and the drain 40 are attached to the partial container 22 and correspond to the second compartment 28. Preferably, the fill/discharge assemblies 30, 32 are color coded or otherwise labeled or marked so that a user can distinguish between the first and the second compartment 18, 28 and thereby correctly match the first fluid with the first compartment 18 and the second fluid with the second compartment 28. Further, the fill/discharge assemblies 30, 32, the vents 34, 36, and the drains 38, 40 are industry standard components so that the tank 10 can be utilized with other fluid storage systems.

Referring now to FIGS. 6 and 7, the partial container 22 is joined to the unitary container 12 at the lap joint 50, and the unitary container 12 is formed of multiple panels connected at lap joint seams (not shown). All of the lap joints are formed during a suitable joining process, such as thermowelding. The lap joint 50 joining the partial container 22 to the unitary container 12 is constructed such that forces generated as a result of filling the second compartment 28 are directed in a shear vector as opposed to a peel vector. This construction produces a joint that has a breaking strength equal to that of the lap joint seams of the unitary container 12. When the first compartment 18 is filled, the tank 10 is under normal stresses associated with a conventional single compartment tank.

The tank 10 can be constructed to have any desired capacity, and, preferably, the capacity of the tank 10 ranges from 100 to 50,000 gallons. In such a construction, the lap joints are preferably about two inches wide so that the tank 10 is suitably strong to support such a large volume of fluid. Additionally, all of the lap joint seams are barrier-coated over the inner and outer surfaces to prevent fluid from wicking through the nylon.

An exemplary description of the operation of the tank 10 follows. It will be apparent to one of ordinary skill that the operation can carried out in any logical order and is not limited to the sequence presented below. The following description is for illustrative purposes only and is not intended to limit the invention in any manner.

The tank 10 is pliable so that it can be collapsed and folded into a compact mass for shipment and storage. To fill the tank 10, the user unfolds or unrolls the collapsed tank 10 onto a surface with the fill/discharge assemblies 30, 32 facing away from the surface. If the user desires to fill the tank with only the first fluid, then the user closes the drain 38, opens the vent 34, and attaches a hose to the fill/discharge assembly 30 and fills the first compartment 18 with a desired volume of the first fluid. Optionally, the user can fill the unitary container 12 to its maximum capacity, as illustrated in FIG. 3. On the other hand, if the user desires to fill the tank with only the second fluid, then the user closes the drain 40, opens the vent 36, and attaches a hose to the fill/discharge assembly 32 and fills the second compartment 28 with a desired volume of the second fluid. FIG. 4 illustrates the tank 10 when the partial container 22 is filled to its maximum capacity. If the user desires to fill the tank 10 with both the first and the second fluids, then the user conducts both of the steps described previously in this paragraph, in any order or simultaneously, such that both the unitary container 12 and the partial container 22 are partially filled, as shown, for example, in FIG. 5. When the filled tank 10 is not in use, the fill/discharge assemblies 30, 32, the vents 34, 36, and the drains 38, 40 are all in a closed condition.

To discharge fluid from the tank 10, the user can apply pressure to the tank 10 so that the tank 10 collapses and thereby forces the fluid to flow out of the first and the second compartments 18, 28, or, alternatively, the user can fill one of the first and the second compartments 18, 28 to displace the second portion 12B and thereby force the fluid to flow out of the other of the first and the second compartments 18, 28. For example, if the tank 10 solely contains the first fluid, then the user can open the fill/discharge assembly 30, attach a hose to the fill/discharge assembly 30, and apply pressure to the tank 10 to force the first fluid from the first compartment 18 and through the hose. Alternatively, the user can open both the fill/discharge assemblies 30, 32, attach hoses to both the fill/discharge assemblies 30, 32, and fill the second compartment 28 with the second fluid. As the second compartment 28 fills, the second portion 12B of the unitary container 12 moves towards the first portion 12A of the unitary container 12 to thereby reduce the volume of the first chamber 18 and force the first fluid through the hose attached to the fill/discharge assembly 30. Thus, while the second compartment 28 is in a fill mode, the first compartment 18 is in a discharge mode. The situation is reversed for discharging the second fluid from the second container 28. If the tank 10 contains both the first and the second fluids, then the user can optionally discharge both fluids at the same time through the fill/discharge assemblies 30, 32.

The tank 10 can also be used to circulate fluids from one of the first and the second compartments 18, 28 to the other of the first and the second compartments 18, 28. For example, fresh water can be stored in one of the compartments, discharged from the compartment, used, and then stored in the other compartment as waste water. Similarly, fresh petroleum product can be stored in one of the compartments, discharged from the compartment, used, and then stored in the other compartment as waste petroleum product.

The tank 10 according to the invention is a dual-compartment, multi-purpose, portable collapsible container for static storage of fluids. The unique design of the tank 10 enables multiple means of circulation and/or storage of dissimilar and flowable petroleum, water, water-based fluid products, and other fluid products. The tank 10 can be deployed multiple times in various locations to store the petroleum, water, water-based fluid products, or other fluid products. Further, because one tank 10 can be used to store more than one type of fluid and effectively replaces two types of tanks with one, the cost of inventorying collapsible containers is decreased.

While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. For example, the relative sizes of the unitary tank 12 and the partial tank 22 can vary over a wide range to accommodate prospective uses of the multi-compartment tank. Further, whereas the invention has been described with respect to tank with two compartments, the invention contemplates three or more compartments by the addition of one of more additional partial containers 22 to the unitary tank 12 and/or to the partial container 22 or other added partial tanks. Reasonable variation and combination are possible with the scope of the foregoing disclosure without departing from the spirit of the invention, which is defined in the appended claims. 

1. A collapsible tank comprising: a unitary container formed of a first contiguous wall having an inner surface and an outer surface, the inner surface of the first contiguous wall defining a first compartment for storing a first fluid; and a flexible partial container formed of a second contiguous wall having an inner surface, an outer surface and an open end; wherein the open end of the second contiguous wall is mounted to the first contiguous wall to divide the first contiguous wall into a first portion and a second portion and to form a second compartment between the inner surface of the second contiguous wall and the outer surface of the second portion of the first contiguous wall for storing a second fluid.
 2. The collapsible tank according to claim 1, wherein the second contiguous wall is about half of the size of the first contiguous wall.
 3. The collapsible tank according to claim 1, wherein the second portion of the first contiguous wall is flexible and movable relative to the first portion of the first contiguous wall and the second contiguous wall to change the relative volumes of the first and the second compartments.
 4. The collapsible tank according to claim 3, wherein an increase in the maximum volume of one of the first and the second compartments corresponds to a decrease in the maximum volume of the other of the first and the second compartments.
 5. The collapsible tank according to claim 4, wherein the maximum volumetric increase and decrease of the first and the second compartments are of substantially equal magnitude.
 6. The collapsible tank according to claim 1, wherein the first and the second compartments have comparable maximum capacities.
 7. The collapsible tank according to claim 1 and further comprising a fill/discharge assembly, a vent, and a drain mounted to each of the first contiguous wall and the second contiguous wall.
 8. The collapsible tank according to claim 1, wherein the first contiguous wall comprises a fluid barrier.
 9. The collapsible tank according to claim 8, wherein the fluid barrier comprises an inner surface fluid barrier on the inner surface of the first contiguous wall and an outer surface fluid barrier on the outer surface of the fluid barrier.
 10. The collapsible tank according to claim 9, wherein the inner surface fluid barrier and the outer surface fluid barrier comprise a polymer coating.
 11. The collapsible tank according to claim 10, wherein one of the inner surface fluid barrier and the outer surface fluid barrier comprises a polyester coating and the other of the inner surface fluid barrier and the outer surface fluid barrier comprises a polyether coating.
 12. The collapsible tank according to claim 9, wherein the second contiguous wall comprises an inner surface fluid barrier on the inner surface thereof.
 13. The collapsible tank according to claim 12, wherein the inner surface fluid barrier of the second contiguous wall comprises the same material as the outer surface fluid barrier of the first contiguous wall.
 14. The collapsible tank according to claim 13, wherein the inner surface fluid barrier of the second contiguous wall and the outer surface fluid barrier of the first contiguous wall comprises one of a polyester and a polyether coating.
 15. The collapsible tank according to claim 1 and further comprising a lap joint at a junction between the first contiguous wall and the second contiguous wall.
 16. The collapsible tank according to claim 15, wherein the lap joint is thermowelded.
 17. The collapsible tank according to claim 1, wherein the first fluid and the second fluid are different fluids.
 18. The collapsible tank according to claim 17, wherein the first fluid is one of a fuel and water, and the second fluid is the other of the fuel and the water.
 19. A collapsible tank comprising: a flexible container having an interior surface defining a maximum volumetric capacity; and a flexible partition mounted to the interior surface of the container to divide the container into a first compartment with a first volume for storing a first fluid and a second compartment with a second volume for storing a second fluid; wherein the partition has sufficient size and pliability so that it is movable within the container to reciprocally change the first and second volumes.
 20. The collapsible tank according to claim 19, wherein the partition is sized so that first and second compartments each have a maximum capacity comparable to the maximum volumetric capacity of the container. 